types of needles and sewing thread

8/7/2019 Types of Needles and Sewing Thread

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Lecture # 14

Type of Needles; theirimportance and sewing

thread


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Needles Parts

The Shank

The Shoulder

The Blade Long Groove

Short Groove

The Eye The Point and the Tip


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Needle Parts

Short Groove:This groove is at the side of the needle and above and below the eye assists inloop formation

The Eye:

The most critical part, since its shape ensures low friction between the needleand the sewing thread and also proper loop formation. In some needles the eyeis larger then the thickness of the working part of the needle, to reduce thefriction between the needle and the thread. But it has its drawbacks with delicatefabrics where some times needle holes are visible

The PointThis is the most important since the shape of the point is directly related to the

type of fabric. Its selection is critical since it could be the source of damagingseam lines and cutting/fraying of fabric


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Design Features of

Needle

Needles can help in

Reducing puckering

Reducing Fabric damage

Reducing Needle Heating


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Needle Size

Needles are available invarious sizes and the choiceof size is determined by thefabric and thread to be

used

Correct size is essential forbetter sewing performance

The size is the thickness ofthe needle at the centerpoint


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Needle Size if not conformed

Needle small for the thread: It will not pass through the needle, even if it does there would be

excessive abrasion, hence thread breakages Operator will have to re-thread the machine and repair the seam

Fine needle for heavy plies: Will cause the needle to be deflected or distorted Resulting is slippage and skip stitches Resulting in needle breakage

Larger Needle for the thread:

Puckering due to fabric distortion Large needle holes and damage fabric appearance along seamlines

Slippage of stitches


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Needle Size if not conformed

Bent Needle Cause slip and poor seam appearance Mainly due to operator negligence Incorrect needle size

Burred orD

amageN

eedle point Can cause fabric damage in woven which will cause abraided or fluffy seams In Knitted fabric it can cut the loop giving rise to ladder effect.

Adequate Time to Change Needles: Needle some times have to be changed in rear heavy fabric situations after

every 2-4 hours

Needle Points: Different Needle points are used for different fabrics and an undesirable

needle point can also cause damage to the fabric.


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Needle Points

There are two sub classes

1. Cutting Points

2. Cloth Points


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Cutting PointN

eedles Used for Leather or

Plastic (sheetingmaterials)

These materials haveno gaps in the surface

The needle point mustbe designed to cut thesurface forpenetration

Cut point needleshave sharp tips

Are available in widevariety of cross-sectional shape


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Cloth PointN

eedles Used for sewing textile materials

Other words used in sewing materials which

have spaces between them

The points have round cross-sectionalshape

Main selection criteria of the needle is thematerial it is used on either woven orknitted


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Cloth PointN

eedles Knitted fabrics have an inherent problem of

unraveling and ladder effect if a loop is broken

The criteria is to use a needle which could slightlydeflect the loops and penetrate the fabric avoiding todamage the fabric

The best possible shape to be use for knitted fabric isthe ball point needle

Ball Point needles come in different sizes Light-Medium-Heavy. Depending upon the fabric thickness


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Cloth PointN

eedles Woven fabrics have yarns interlacing with various

densities

A Set point needle is used

For greater strength and better penetration

Due to natural spaces in woven fabrics the needledoes not require to make spaces

As long as it does not damage or break the warp orthe weft


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Needle Material

Steel

Polished

Electroplated due to better corrosiveresistance

Also plating is done by nickel or

chromium Chromium is preferred

types of needles and sewing thread

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